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South Dakota Wetlands EarthCache EarthCache

Hidden : 6/7/2011
Difficulty:
2.5 out of 5
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Geocache Description:

This EarthCache is located at the Outdoor Campus in Sertoma Park. You must enter the main visitors center to answers some of the questions.

Entry is free.

Hours of operation are:
Monday - Friday: 8am to 5pm
Saturday: 10am to 4pm
Sunday: 1pm to 4pm

Questions

To complete this EarthCache you must answer the questions below and then by clicking on my profile name, messaging me the answers. Any logs without messaging me ALL of the answers will be deleted. Please do not post any answers in your log.

Stage 1:
Enter the Outdoor Campus visitors centre and find the South Dakota outdoor exhibit(It's on the left as you walk in the front door). You will need to locate the exhibit on Wetlands and answer the following questions:
1) People used to think wetlands were ___(1a)__ swamps and ought to be __(1b)__ and "__(1c)__".
2) Of the six animals listed that live in wetlands, name two of them listed in the Wetlands exhibit?
3) What is one thing that Wetlands do to pollutants?

Stage 2:
Explore the Outdoor Campus (Sertoma Park) and locate an area that contains a "Wetland". Do not get confused with an Oxbow. An Oxbow is located South East of the visitors centers rear doors. Hint: Wetlands are located further to the west..
4) Describe the Wetlands appearance?
5) Does the Wetland appear to be "acting like a sponge"?
6) What are the coordinates of this wetland?
7) Upload a photo of yourself or the wetland (Optional)

Stage 3
Information on this page:
8) How many temporary wetlands can be found Eastern South? (Found under Natural Wetlands)
9) What is the least common type of wetland?

South Dakota Wetlands

Most of eastern South Dakota lies in the glaciated prairie pothole region of North America, and the landscape is dotted by wetlands sometimes numbering over 100 per square mile. An early settler recalled that as late as 1903:
....low knolls are separated by saucer-like depressions, in which impounded water often stands the year around....in the main rainwater which falls upon the uplands has to escape by seepage or evaporation. Little ponds and marshes are found in almost innumerable places scattered all over the county.

Whether called ponds, marshes, potholes, sloughs, swamps, or low spots, wetlands have been the subject of more legislative hearings, letters to editors, community debates, and disagreements among neighbours than any other feature of the landscape. Factual information is needed before citizens can make informed decisions about the role of wetlands in South Dakota in the next century.

This report summarizes the abundance and characteristics of eastern South Dakota wetlands -- the potholes, impoundments, natural lakes, rivers, and other water bodies mapped by the National Wetlands Inventory (NWI). Earlier wetland inventories often underestimated wetland acreage because they focused on specific types of wetlands, for example, only those valuable for duck production or only those deep enough to hold water for a certain length of time.

The NWI mapped wetlands without regard to specific functions or size. Therefore, this report is based on the most comprehensive inventory of eastern South Dakota wetlands ever conducted.

When controversy erupts over wetlands, especially in agricultural regions like eastern South Dakota, sides are usually drawn over issues of property rights, economics, and wetland values. Some people, farmers who have a direct economic stake in how wetlands on their property are used, believe the most appropriate use is drainage followed by crop production. Others rally to preserve wetlands, but their arguments often are based on less quantifiable values.

During the early settlement period, wetlands were generally regarded as wastelands and impediments to agriculture and travel. Yet even then, wetland benefits were recognized.

The site of the first settlement in Kingsbury County was chosen because of nearby wetlands. A pioneer recalled that:
As we came from near New Ulm, Minn., and finding lots of sloughs lying between Lake Badger and Lake Thistad, and [as] these sloughs were covered with muskrat houses, [we] decided to locate here and build these dugouts and spent the winter here trapping.

Agricultural drainage of eastern South Dakota's wetlands began in the late 1800s. One of the first cooperative drainage ditches was dug in 1886 by a group of Clay County farmers. A year later, construction of a similar ditch was blocked in court by farmers who objected to the ditch crossing their lands.

Drainage increased after WWII in conjunction with high crop prices and more mechanized farming. For many years, the U.S. Department of Agriculture (USDA) provided technical and financial assistance to help farmers drain wetlands.

As concerns increased about the effects of wetland drainage on wildlife, the U.S. Fish and Wildlife Service (USFWS) began paying landowners to preserve wetlands. Easements are a one-time payment to landowners who agree not to drain, burn, fill, or level their wetlands. The USFWS also purchased wetlands outright. As of 1997, revenue from federal duck stamp sales had purchased about 700 Waterfowl Production Areas (WPAs) and perpetual easements on about 25% of remaining eastern South Dakota wetlands, all from willing sellers.

Confusion about the importance of wetlands is understandable. For years, one department of the government paid for wetland drainage while another paid to prevent it.

Today, we know much more about how wetlands help maintain a healthy environment for humans and wildlife, and both agricultural and non-agricultural interests are beginning to appreciate the role wetlands play in the eastern South Dakota landscape.

That role often is divided into three critical segments:

(1) benefits to wildlife,

(2) benefits to humans, and

(3) contributions to the normal movements of water throughout the landscape, known as hydrology.

Wetlands and Wildlife

When explorers and settlers first crossed the wet prairies of eastern South Dakota they were greeted by clouds of waterfowl that had depended on the region for breeding and migration for more than 10,000 years.

The most productive duck nesting grounds of all - an area that often produced twenty or more broods to the square mile - were the glaciated grasslands of the northern Great Plains, studded with potholes, sloughs, and shallow marshes that made ideal habitat for mallards, pintails, canvasbacks, and other ducks of more than a dozen species....The spring and autumn migrations of the waterfowl were awe-inspiring sites to the first explorers who saw them. From the....prairie sloughs and potholes still unseen by white men, swans, geese and ducks... streamed southward each fall to concentrate by the millions on the bays, marshes, and rivers of the South.

Despite extensive wetland drainage and loss of upland nesting cover, the prairie pothole region of eastern South Dakota remains one of the most productive waterfowl breeding areas of North America. It is the combination of small and shallow wetlands with larger and deeper wetlands that makes eastern South Dakota so attractive to breeding ducks.

Temporary and seasonal wetlands, most less than half an acre in size, thaw quickly in the spring. Pairs of dabbling ducks -- species such as mallards, pintails, and blue-winged teal -- will seek seclusion from other members of their species when they are preparing to nest. They find this privacy on small wetlands. These small wetlands also provide a rich source of aquatic insects, snails, and other invertebrates. Hens need this protein-and calcium-rich food to produce eggs.

A series of wet years on the prairies, when small, shallow wetlands hold water throughout the breeding season, can result in continental duck population explosions.

Deeper wetlands, that thaw later and hold water throughout the summer in most years, attract different ducks. These deeper wetlands provide breeding habitat for diving ducks such as canvasbacks and redheads.

Later in the season, many dabbling ducks will lead their broods to these deeper wetlands. And in the fall, migrating ducks and geese interrupt their southward journey to rest and feed on these wetlands, making eastern South Dakota a waterfowl management area of international importance and a paradise for waterfowl hunters.

Besides ducks, over 100 fish, 80 bird, 25 mammal, 17 amphibian, and 10 reptile species depend on eastern South Dakota wetlands. Some upland wildlife, such as ring-necked pheasants and white-tailed deer, use wetlands during the winter to survive prolonged cold and blizzards. Winter wind velocities in wetlands may be 95% less than in nearby shelter-belts, making wetlands valuable winter cover for many resident wildlife species.

Wetlands provide habitat for more than 200 species of wildlife that live in or migrate through eastern South Dakota.

Wetlands and Water Movement


Wetlands play an important role in the natural movement of water both above and below ground. When water from melting snow or rain runs into a wetland, it is stored there until it evaporates or soaks into the ground. Because wetlands release water slowly, one of the best known hydrologic benefits of wetlands is flood control.

Wetlands usually lie within deeper depressions that are only filled during very wet years. If a wetland is drained, water from the depression may have nowhere to collect and will spill into streams and spread over low-lying properties.

About 16,500 wetlands out of 50,200 (33%) in the Vermillion River watershed in southeastern South Dakota flow into artificial drainage ditches. Restoring these drained wetlands could store an amount of water roughly equal to half the annual flow on the flood-prone Vermillion River in a wet year.

The water in wetlands that soaks into the soil recharges ground water supplies, providing water for farm and home use. In fact, in the clay-rich soil areas in eastern South Dakota, the only significant source of ground water recharge may be wetlands. Ground water also may move upward, maintaining soil moisture during dry periods, thereby protecting crops, lawns, and other vegetation during drought.

Wetlands have other hydrologic functions, such as stabilizing stream flows and reducing pollutants entering rivers and lakes. About 239 South Dakota cities and towns use created wetlands for secondary or tertiary sewage treatment.

Overview of Wetland Resources

There are 947,652 wetlands -- potholes, dugouts, reservoirs, and natural lakes -- in eastern South Dakota. These wetlands occupy a total of 2,137,929 acres. Rivers and streams account for another 69,300 acres. These estimates represent the number and area of wetlands under "typical" conditions.

Wetlands cover about 9.8% of the total landscape of eastern South Dakota. Extremes are Lincoln County (4.6%) and Sanborn County (15.6%).

Most eastern South Dakota wetlands are small; about 60% are less than half an acre, and almost 75% are smaller than an acre.

About 83% of temporaries, 55% of seasonals, and 21% of semipermanents are smaller than 1 acre. In fact, less than 5% of all wetlands are larger than 5 acres.

Legislation and government programs that protect only wetlands larger than 1 acre put most eastern South Dakota wetlands at risk of being drained. About 465,500 wetlands -- about half of all eastern South Dakota wetlands -- are jeopardized by proposals to eliminate protection for frequently farmed wetlands and wetlands smaller than 1 acre.

Wetland distribution in Eastern South Dakota

Eastern South Dakota wetlands were formed by retreating glaciers, so wetlands tend to be most common in areas covered by the last glaciers. The landscape of eastern South Dakota is geologically too young for rivers and streams to be well developed. About 80% of the landscape in many areas of eastern South Dakota drained into wetlands before European settlement.

Watershed size and terrain, average annual precipitation and evaporation, soil type, and ground water interactions all determine a wetland's water permanence (water regime).

High-relief landscapes with deep depressions, sometimes called knob-and-kettle terrain (as in parts of Marshall County), often contain many semipermanent wetlands. Shallow temporary and seasonal wetlands are usually most abundant in low-relief terrain like that in Beadle, Spink, and Brown counties.

Natural wetlands

The 520,379 temporary wetlands in eastern South Dakota cover just over 390,000 acres. They are the most common type of wetland in the region, making up 55% of the total number of wetlands.

Temporaries are most common in Beadle, Brown, Spink, and Hand counties where their combined number is over 146,000. Temporaries are least common outside the area covered by the last glaciers, such as in Buffalo and Union counties where they total only about 4,300. About 77%, or 399,000 temporary wetlands, are in cropland. Location, coupled with ease of drainage, makes them vulnerable to loss.

A total of 334,699 seasonal wetlands in eastern South Dakota cover over 553,500 acres. They are abundant in scattered localities, but are particularly common in an 80 mile-wide band that runs diagonally from Eureka in McPherson County southeastward to Salem in McCook County.

Edmunds County alone contains 22,225 seasonal wetlands. The fewest seasonals -- only 998 -- are found in Union County.



Semipermanents, with their typical mix of cattails and open water, are what first comes to mind when many people picture "wetlands." Actually, semipermanents are uncommon -- they number only 23,997 and occupy about 377,600 acres. All together, they make up only about 2.5% of all wetlands in eastern South Dakota.

Semipermanents are most often found in a few areas of northeastern South Dakota including the counties of Marshall, Day, Roberts, Grant, and Deuel. The number of semipermanents in these counties total 11,828 -- almost half the total number of all semipermanents in eastern South Dakota. The smallest number of semipermanents, 22, occurs in Hughes County.

Permanent wetlands are the least common type of natural wetlands; there are only 603 east of the Missouri River. However, these wetlands are large and cover over 194,000 acres.

The highest density of large permanent wetlands (lakes) occurs along the west side of the Big Sioux River from Day County south to Lake County. Lake Poinsett in Brookings and Hamlin counties, at 10,100 acres is the largest natural permanent wetland in South Dakota.

Sometimes large semipermanent wetlands fill up and function as lakes, but the water eventually recedes and they once again become dominated by cattails or similar vegetation, something that rarely happens to lakes. Lake Thompson in Kingsbury County is a good example. It has repeatedly filled up and then dried up in the past. In the mid-1980s and 1990s Lake Thompson swelled to nearly 20,000 acres, making it the largest natural "lake-like" body of water in the state. Although the changes are usually not as dramatic, small wetlands also are very dynamic.

Rivers cover about 69,300 acres of eastern South Dakota. The major rivers in eastern South Dakota are the Big Sioux, Vermillion, James, and Missouri. Creation of the Missouri River reservoirs destroyed much of the riverine habitat in eastern South Dakota by changing those river reaches to impoundments. Some free flowing reaches still exist, bordering Charles Mix, Bon Homme, Yankton, Clay, and Union counties, but even in these areas the natural hydrology has been greatly altered because dams control the flow of water.

Rivers in the glaciated prairie pothole region tend to be narrow with weakly developed channels. Consequently they tend to be flood-prone when snow melts quickly or after heavy rains.

The Big Sioux River was once nick-named the "Silvery Sioux." In 1838, Joseph Nicollet described the Big Sioux near Brookings as "a stream of clear, swift-running water" flowing over a "pebbly bottom." Only rivers that flow mainly through pastureland -- like the Yellowbank River in Grant County -- still fit this description.

Healthy riverine habitats often have high biodiversity. Although flowing freshwater comprises only about 1/1 millionth of all the water on earth, 50% of all animal species inhabit creeks, streams, and rivers. In fact, one of the best ways to evaluate the health of a river is to sample its invertebrates.

Created wetlands

Created wetlands are usually constructed in one of two ways: by excavating a hole or channel or by blocking the natural flow of water with a dam, thereby creating an impoundment.

The only types of excavated wetland discussed in this report are dugouts -- rectangular holes dug to intercept surface runoff or to expose the water table. Generally dugouts are constructed to provide water for livestock. A total of 56,827 dugouts are scattered across eastern South Dakota, of which 35,086 (62%) were excavated in 22,530 natural wetlands. The remaining 21,741 dugouts were constructed outside of natural wetlands or in stream channels.

Although dugouts may occasionally enhance natural wetlands by providing a deep-water refuge for duck broods or fish, their impact may be negative when spoil from the excavation is piled in the natural wetland.

Eastern South Dakota impoundments may be subdivided into two broad groups; (1) small impoundments, often called stock dams, and (2) large (more than 100 acres), permanent reservoirs. All impoundments are constructed by creating a dam in a channel. Consequently, most are found on or near the Missouri River, outside areas of recent glaciation.

Although the technology of damming up a ravine or intermittent stream to create a stock dam is superficially like that of creating a large reservoir on a mainstem river or major tributary, the results for landowners and wildlife are very different. Both types of constructed wetlands can effectively impound runoff; however, livestock and wildlife relate to the shoreline of an impoundment, making little or no use of the center of these bodies of open water. Stock dams typically have much greater shoreline length relative to their size than do large reservoirs. Therefore, small stock dams provide greater benefits to landowners and wildlife than does a single large reservoir of the same total area.

Some stock dams provide added benefits of recreational fishing. Stock dams also may enhance cattle performance by improving stock distribution and range and pasture utilization. Several federal agencies offer cost sharing and technical assistance for creating these kinds of wetlands.

In eastern South Dakota, most stock dams are a few acres in size and have a 200-600 acre watershed. Most contain between 12 and 20 acre-feet of water when full. A total of 11,836 stock dams have been constructed in eastern South Dakota covering 106,740 acres.

Large reservoirs are permanent impoundments constructed for flood control, hydroelectric power generation, domestic or agricultural water supplies, or for recreation. The 75 reservoirs in the region cover 256,826 acres, or about 12% of the total area of surface water in eastern South Dakota. This total acreage includes the area of Missouri River reservoirs within the counties on the east side of the river.

Approximately 95% of the reservoir area in eastern South Dakota is made up by lakes Lewis and Clark, Francis Case, Sharpe, and Oahe on the Missouri River.

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